Pillararene-based supramolecular systems for theranostics and bioapplications

As an emerging type of important macrocycles for supramolecular chemistry, pillararenes and their derivatives have been widely studied and applied in numerous fields, which intensively promotes the development of chemistry, materials science and biology.Pillararene-based theranostic systems are of special interest in the biological and medical areas as they have shown very promising results. Owing to easy preparation, reliable guest affinity, good biocompatibility and stability, pillararenes are frequently used to construct functional biomaterials. On one hand, pillararenes can either be used individually or form diversiform self-assemblies such as micelles, nanoparticles and vesicles to increase water solubility and biocompatibility of drugs.On the other hand, it is promising to modify solid materials like framework materials, silica nanoparticles and graphene oxides with pillararene derivatives to enhance their functions and controllability. In this review, we summarize recent endeavors of pillararene-based supramolecular systems with theranostics and other biological applications comprising drug delivery/chemotherapy, photodynamic/photothermal therapy, antimicrobials, bioimaging, etc. By introducing several typical examples, the design principles, preparation strategies, identifications and bio-applications of these pillararene-based supramolecular systems are described. Future challenges and directions of this field are also outlined.     

Recent advances in upper rim functionalization of resorcin[4]arene derivatives: Synthesis and applications

Abstract

During the last decades, resorcin[4]arenes have drawn much attention in the field of supramolecular chemistry because of their practical applicability in different areas. Therefore, many scientists have investigated this class of derivatives in recent years. In this article, we comprehensively reviewed a brief literature survey on the chemistry of upper rim functionalization of calix[4]resorcinarene derivatives and their applications concerning optical chemosensors, liquid crystal materials, host-guest systems, catalysis, drug delivery, biological activities, and analytical applications. This short review describes the survey of literature synthesis and upper rim functionalization of resorcin[4]arenes and their different application published in the last six years (2015–2020).     

葫芦脲在色谱固定相中的研究进展

葫芦脲是超分子化学中继冠醚、环糊精、杯芳烃之后发展起来的又一类新型高度对称的桶状大环主体分子,是一种由多个甘脲单元组成的大环穴状配体,被誉为"第四代超分子化合物"。由于其具有特殊的分离选择性和稳定性,在超分子化学和色谱的交叉领域备受关注。本文从葫芦脲的结构特征出发,侧重概述了葫芦脲同系物及其衍生物在色谱固定相中的研究现状和进展。     

Recent advances and perspectives on supramolecular radical cages

Supramolecular radical chemistry has been emerging as a cutting-edge interdisciplinary field of traditional supramolecular chemistry and radical chemistry in recent years. The purpose of such a fundamental research field is to combine traditional supramolecular chemistry and radical chemistry together, and take the benefit of both to eventually create new molecules and materials. Recently, supramolecular radical cages have been becoming one of the most frontier and challenging research focuses in the field of supramolecular chemistry. In this Perspective, we give a brief introduction to organic radical chemistry, supramolecular chemistry, and the emerging supramolecular radical chemistry along with their history and application. Subsequently, we turn to the main part of this topic: supramolecular radical cages. The design and synthesis of supramolecular cages consisting of redox-active building blocks and radical centres are summarized. The host–guest interactions between supramolecular (radical) cages and organic radicals are also surveyed. Some interesting properties and applications of supramolecular radical cages such as their unique spin–spin interactions and intriguing confinement effects in radical-mediated/catalyzed reactions are comprehensively discussed and highlighted in the main text. The purpose of this Perspective is to help students and researchers understand the development of supramolecular radical cages, and potentially to stimulate innovation and creativity and infuse new energy into the fields of traditional supramolecular chemistry and radical chemistry as well as supramolecular radical chemistry.

This Perspective summarizes the recent developments of supramolecular radical cages including the design and synthesis of radical cages, their interesting host–guest spin–spin interactions and applications in radical-mediated/catalyzed reactions.     

Progress of 3-aminopyridine-based amide,urea, imine and azo derivatives in supramolecular gelation

Supramolecular gels derived from low molecular weight gelators are considered to be fascinating soft and smart materials. Gelators of this class form gel networks involving noncovalent interactions and show various applications in many areas. The structural softness and the arrangement of the gelator molecules in the aggregated state have the collaborative effect to intensify the properties of the molecules for their potential applications in material chemistry. Of the various properties, stimulus responsibility is a desired property of supramolecular gel that finds profound application in sensing. In this review, a comprehensive summary of the work on 3-aminopyridine-based amide, urea, imine and azo gelators of different architectures indicating their different uses in supramolecular chemistry has been focused.     

Diketopyrrolopyrrole-based functional supramolecular polymers: next-generation materials for optoelectronic applications

The very concept of dye and pigment chemistry that was long known to the industrial world underwent a radical revision after the discovery and commercialization of dyes such as mauveine, indigo, and so on. Apart from their conventional role as coloring agents, organic dyes, and pigments have been identified as indispensable sources for high-end technological applications including optical and electronic devices. Simultaneous with the advancement in the supramolecular chemistry of π-conjugated systems and the divergent evolution of organic semiconductor materials, several dyes, and pigments have emerged as potential candidates for contemporary optoelectronic devices. Of all the major pigments, diketopyrrolopyrrole (DPP) better known as the ‘Ferrari Pigment’ and its derivatives have emerged as a major class of organic functional dyes that find varied applications in fields such as industrial pigments, organic solar cells, organic field–effect transistors, and in bioimaging. Since its discovery in 1974 by Farnum and Mehta, DPP-derived dyes gained rapid attention because of its attractive color, synthetic feasibility, ease of functionalization, and tunable optical and electronic properties. The advancement in supramolecular polymerization of DPP-based small molecules and oligomers with directed morphological and electronic features have led to the development of high performing optoelectronic devices. In this review, we highlight the recent developments in the optoelectronic applications of DPP derivatives specifically engineered to form supramolecular polymers.     

Cucurbiturils–a New Family of Host Molecules

The supramolecular chemistry of cucurbituril, a synthetic receptor, is fascinating because of the remarkable guest binding behavior of the host. Although cucurbituril is potentially as useful as crown ethers, cyclodextrins, and calixarenes in many applications, its chemistry has not been developed much until recently because of several shortcomings. Recently we synthesized cucurbituril homologues and derivatives. These new members of the cucurbituril family have expanded the scope further, and interest in them has grown enormously. The diversity in guest binding behavior has led to many interesting studies such as redox control of guest binding, stabilization of charge-transfer complexes inside the host cavity, encapsulation of drug molecules, formation of redox-controllable vesicles, and so on. The cucurbituril homologues and derivatives thus provide new opportunities in many areas of supramolecular chemistry including recognition, catalysis, separation, transport, and many others.     

J-aggregates: from serendipitous discovery to supramolecular engineering of functional dye materials

J-aggregates are of significant interest for organic materials conceived by supramolecular approaches. Their discovery in the 1930s represents one of the most important milestones in dye chemistry as well as the germination of supramolecular chemistry. The intriguing optical properties of J-aggregates (in particular, very narrow red-shifted absorption bands with respect to those of the monomer and their ability to delocalize and migrate excitons) as well as their prospect for applications have motivated scientists to become involved in this field, and numerous contributions have been published. This Review provides an overview on the J-aggregates of a broad variety of dyes (including cyanines, porphyrins, phthalocyanines, and perylene bisimides) created by using supramolecular construction principles, and discusses their optical and photophysical properties as well as their potential applications. Thus, this Review is intended to be of interest to the supramolecular, photochemistry, and materials science communities.     

硫原子桥联芳基取代/稠合四硫富瓦烯

近年来,四硫富瓦烯(Tetrathiafulvalene,TTF)衍生物的设计合成、超分子组装、组装材料的物理性能研究及其在有机电子器件中的应用引起了人们广泛的研究兴趣。在本文中,我们简略综述硫原子桥联芳基取代/稠合四硫富瓦烯衍生物(Ar-S-TTF)的最新研究进展,包括其高效合成、电化学及光学性能研究、分子的结构特征/空间堆积方式,以及此类分子与球形原子簇(富勒烯、杂多酸)之间的超分子组装及组装材料的性能。     

生物医用类环糊精/聚合物(准)聚轮烷

环糊精及其衍生物具有“内疏水、外亲水”的特殊分子结构,可与许多客体分子包结形成包合物。利用环糊精与聚合物的包结作用构建稳定、结构可控并具有广泛应用前景的生物医用材料是材料及医学界研究的焦点之一。本文介绍了环糊精基(准)聚轮烷的概念及其组装驱动力,同时围绕由环糊精和聚合物组装形成的(准)聚轮烷在生物医用方面的研究包括药物载体(如超分子凝胶、超分子胶束、超分子纳米囊泡、药物键合(准)聚轮烷、刺激响应型(准)聚轮烷等)、基因载体、多重识别与靶向、形状记忆材料及其它相关领域工作进展作一概述。     

四硫富瓦烯衍生物在有机光电功能材料方面的研究进展

四硫富瓦烯(TTF)及其衍生物不仅是分子导体的有效构筑模块之一, 而且在材料化学的诸多领域显示了广阔的应用前景. 本工作综述了近几年TTF及其衍生物在非线性光学、分子光电器件、光伏器件及光致变色方面的最新研究进展.     

Recent progress of core-substituted naphthalenediimides: highlights from 2010

Core-substituted naphthalenediimides (cNDIs) are rapidly emerging as a powerful strategy to create functional nanomaterials and their implications in biological and supramolecular chemistry are significant. Recent developments in the synthesis of cNDIs have allowed several groups to probe the function of this interesting class of dye molecules in a molecular and supramolecular sense. Core-substitution of the NDI can be seen as an opportunity to extend the planar, rigid core and could be used to prepare novel structures for applications in organic, biosupramolecular chemistry, biomedicine, materials science and organic solar cells. In this Emerging Area, we provide up-to-date recent progress in the field of cNDIs. We begin with a general discussion and the applications of cNDIs in the field of supramolecular chemistry i.e. generation of nanostructures such as vesicles and nanotubes etc., and we also discuss advances in artificial photosynthesis. Following this is a section on their implications in the field of sensors, particularly DNA intercalation, anion sensing and NDI based pH sensors. Finally, we explore the recent development of cNDIs in organic solar cell applications. We conclude with our views on the prospects of cNDIs in future research.     

Recent Progress in Azopyridine-Containing Supramolecular Assembly: From Photoresponsive Liquid Crystals to Light-Driven Devices

Azobenzene derivatives have become one of the most famous photoresponsive chromophores in the past few decades for their reversible molecular switches upon the irradiation of actinic light. To meet the ever-increasing requirements for applications in materials science, biomedicine, and light-driven devices, it is usually necessary to adjust their photochemical property from the molecular level by changing the substituents on the benzene rings of azobenzene groups. Among the diverse azobenzene derivatives, azopyridine combines the photoresponsive feature of azobenzene groups and the supramolecular function of pyridyl moieties in one molecule. This unique feature provides pH-responsiveness and hydrogen/halogen/coordination binding sites in the same chromophore, paving a new way to prepare multi-functional responsive materials through non-covalent interactions and reversible chemical reactions. This review summarizes the photochemical and photophysical properties of azopyridine derivatives in supramolecular states (e.g., hydrogen/halogen bonding, coordination interactions, and quaternization reactions) and illustrates their applications from photoresponsive liquid crystals to light-driven devices. We hope this review can highlight azopyridine as one more versatile candidate molecule for designing novel photoresponsive materials towards light-driven applications.     

典型锕系超分子组装体的构筑原理及研究进展

锕系超分子化学是锕系元素化学的重要研究领域,可以为乏燃料后处理的配位化学基础研究提供重要信息,并为探索锕系功能材料在发光、传感、催化和分离等方面的功能应用提供关键材料体系。本文介绍了基于锕系金属离子的金属-有机超分子组装体这一新兴领域的最新研究进展。从锕系超分子组装体的构筑原理出发并结合笔者自身研究情况,对基于主客体准轮烷配体的锕系-轮烷配位聚合物、具有闭合结构的锕系配位组装体和基于超分子相互作用的锕系超分子聚合物这三类典型的锕系超分子组装体的研究进展进行了梳理和总结阐述。期望为未来新型锕系超分子组装体的设计合成提供参考,促进相关领域的进步和发展。     

超分子有机膦大环化合物研究进展

有机膦大环化合物是伴随着大环化学的出现而发展起来的．它们不仅具有多变的结构而且非常稳定;不仅能够包结客体分子,还可以与许多过渡金属形成稳定的配位化合物,在主客体化学以及金属有机催化领域中受到人们的广泛关注．由于其独特的性质,有机膦大环化合物在超分子化学的发展中具有重要的地位．本文主要介绍了近些年有机膦大环化合物研究的新进展及其在超分子化学中的应用．     

Cyclodextrins as Protective Agents of Protein Aggregation: An Overview

Cyclodextrins are extensively used in different fields (e.g., catalysis, chromatography, pharma, supramolecular chemistry, bioorganic chemistry, and bioinorganic chemistry), and their applications have been widely reviewed. Their main application in the field of pharmaceutical is as a drug carrier. This review overviews, for the first time, the use of cyclodextrins and their derivatives as antiaggregant agents in a number of proteins (e.g., amyloid‐β, insulin, recombinant human growth hormone, prion protein, transthyretin, and α‐synuclein) and some multimeric enzymes. There are many diseases that are correlated to protein misfolding and amyloid formation processes affecting numerous organs and tissues. There are over 30 different amyloid proteins and a number of corresponding diseases. Alzheimer's disease is the most common neurodegenerative disease. Treatment of these diseases is still a goal to reach, and many molecules are studied in this perspective. Cyclodextrins have also been studied, and they show great potential; as such, further studies could be very promising. This review aims to be a stimulus for the design of new cyclodextrin derivatives to obtain multifunctional systems with antiaggregant activity.     

Chiral benzimidazoles and their applications in stereodiscrimination processes

Chiral aspects of benzimidazoles have been over-shadowed for a long time due to the large number of reports on benzimidazoles in the medical field in numerous categories of therapeutic agents. The vigorous research activity in chiral applications of benzimidazole derivatives started after bifunctional benzimidazoles made their appearance especially in the last 2–3 decades. Thus, chiral benzimidazoles form a comparatively young branch of chiral chemistry. The presence of pyridine and pyrrole type of nitrogens along with the fused benzene ring confer on this class of molecules, special properties including useful nucleophilicity, hydrogen bonding ability and a rigid backbone, all of which play decisive roles in proven chiral applications. The present review aims to cover the synthetic routes to access chiral benzimidazoles and their applications in a plethora of chiral fields including enantioselective organocatalysis, metal-based catalysis, asymmetric transformations involving benzimidazole-N-heterocyclic carbenes, kinetic resolution, benzimidazole-based macrocyclic hosts in chiral supramolecular chemistry and other miscellaneous chiral applications.     

Macromolecules containing bipyridine and terpyridine metal complexes: towards metallosupramolecular polymers

The ability of a broad range of N-heterocycles to act as very effective and stable complexation agents for several transition metal ions, such as cobalt(II), copper(II), nickel(II), and ruthenium(II), has long been known in analytical chemistry. This behavior was later utilized in supramolecular chemistry for the construction of highly sophisticated architectures, such as helicates, racks, and grids. The discovery of macromolecules by Staudinger in 1922 opened up avenues towards sophisticated materials with properties hitherto completely unknown. In the last few decades, the combination of macromolecular and supramolecular chemistry has been attempted by developing metal-complexing and metal-containing polymers for a wide variety of applications that range from filtration to catalysis. The stability of the polymer-metal complex is a fundamental requirement for such applications. In this respect, the use of bi- and terpyridines as chelating ligands is highly promising, since these molecules are known to form highly stable complexes with interesting physical properties with transition-metal ions. A large number of different structures have been designed for many different applications, but polymers based on the application of coordinative forces have been prepared in a few cases only. Furthermore, the synthetic procedures applied frequently resulted in low yields. During the last few years, strong efforts have been made in the direction of self-assembling and supramolecular polymers as novel materials with "intelligent" and tunable properties. In this review, an overview of this active area at the interface of supramolecular and macromolecular chemistry is given.     

Applications of Pillar[n]arene‐Based Supramolecular Assemblies

Macrocycles are an important player in supramolecular chemistry. In 2008, a new class of macrocycles, “pillar[n]arenes”, were first discovered. Research efforts in the area of pillar[n]arenes have elucidated key properties, such as their shape, reaction mechanism, host–guest properties, and their versatile functionality, which has contributed to the development of pillar[n]arene chemistry and their applications to various fields. This Minireview describes how pillar[n]arene‐based supramolecular assemblies can be applied to supramolecular gel formation, reactions, light‐harvesting systems, drug‐delivery systems, biochemical applications, separation and storage materials, and surface chemistry.